The CMA (Competition And Markets Authority) has identified "widespread concerns" about the information people are given by the sites and gathered evidence which it considers reveal breaches of the law.

The CMA has ruled that it must be clear if there are restrictions on using a resold ticket that could result in buyers being denied access to an event; people should know whom they are buying from – for example if the seller is a business and/or an event organiser – and can benefit from their legal rights; and customers need to be told where exactly in a venue they will be seated. It has also broadened the scope of its original investigation

“Today’s CMA announcement that they will take enforcement action against secondary ticketing sites justifies everything FanFair Alliance supporters have campaigned for," said a statement from the FanFair Alliance, the campaign against industrial-scale ticket touting.

“Alongside work from the Advertising Standards Authority and National Trading Standards, we are especially pleased the CMA will expand the scope of their investigation. Beyond suspected breaches of consumer protection law, we believe the largest ticket resale platforms are riddled with bad practice, including speculative ticket listings, pressure selling and collusion with large-scale ticket touts.

“It is has taken far too long to get here, but a Sword of Damocles now hangs over the entire secondary market. If they fail to deliver root-and-branch reforms, we expect the largest resale platforms to face significant consequences.”

The CMA will continue to work closely with partner agencies and enforcers including: the Advertising Standards Authority, National Trading Standards (NTS) and Trading Standards Scotland. Google announced new global resale regulations last week.

Alex Neill, MD of Home Products and Services for consumer watchdog Which?, said: “With people increasingly finding that they have to buy tickets through secondary sites, it's right that the competition authorities are taking action against companies that aren't playing by the rules. Our research has found many websites breaking consumer law by not listing the face value of, or restrictions on, tickets as well as key information, such as block, row and seat numbers.

"This action must now lead to much greater transparency, so that consumers have a better chance of getting the best tickets for popular events."

Richard Davies, founder of face value resale platform Twickets, said: "We welcome the CMA’s move to deepen their investigation into the secondary ticketing market, including commencing action against one site. It is particularly encouraging to see that the CMA have broadened their investigation to span additional issues such as pressure selling and speculative selling, which have plagued consumers for far too long. We look forward to seeing further action being enforced to ensure that fans are better protected against the unscrupulous practices of touts.”

MP Sharon Hodgson, co-chair of the APPG on ticket abuse, said: “It is welcome news that the CMA are now considering enforcement action against the resale platforms, who we know have repeatedly flouted the law of the land, especially after the many years of MPs and campaigners saying just that.

“What is incredibly interesting from this announcement is the fact that the CMA have widened the scope of their investigations from their original terms after they have seen just how broken this market is and the further action needed to fix it.

“This is positive news from an agency who is ultimately instructed to protect consumers from companies disregarding their rights and will be an important step in the right direction to finally put fans first in this market, once and for all.”

A spokesperson for Ticketmaster, which owns the Seatwave and Get Me In! resale sites, said: “It is great to see that the CMA is taking this much-needed step to enforce the law in the UK resale market. We have been working closely with the CMA to ensure that we are compliant with consumer law, offering unparalleled transparency to fans when purchasing tickets.”